By Andrew Bomford
BBC News, Lake Chad
Lake Chad has shrunk from 15,000 to 500 sq miles in 40 years
One of the world's great lakes is disappearing. Lake Chad - shared by Nigeria, Chad, Cameroon, and Niger - has receded to less than 20% of its former volume. Global warming is being blamed, as well as water extraction.
The land is parched dry and dusty but the first hint that there is water comes with the growing numbers of Caltropis dotting the landscape.
These strange, twisted plants have deep tap roots, and where they grow water is usually not far away.
But it did not seem very close as we left the scruffy town of Baga in a battered four-wheel drive jeep, lurching from rut to rut across what was once the lake bed itself.
Just 30 years ago, water covered the whole area. Baga was a waterfront town. Now it is stranded many miles from the lake as the land around it becomes desert. The Sahara is moving southwards.
View from space
To gauge the true scale of the environmental disaster under way at Lake Chad you first have to look at it from space.
From the unblinking eye of a satellite you can see the long decline. Once it was a huge inland sea, and just 40 years ago there was 15,000 square miles of water.
Now the latest satellite pictures put it at just over 500 square miles, and falling.
"Survival becomes a real problem here because we have no means of other livelihood," our driver says.
"We solely depend on the water and when there's not enough we have a serious problem."
At the lake bank, fishermen are pulling small black catfish from a large cylindrical fish trap made from bamboo. The catch is tiny.
"Before, you could fill about 30 of these traps with fish," said the fishermen, Musa Niger. "But now even if I put hundreds of these traps out, I hardly fill one because of the lack of fish."
He said the day's catch was worth about 750 naira (£3), whereas a few years ago he could sometimes earn 15,000 Naira (£60) for a day's fishing.
There is no single cause for the disappearance of Lake Chad.
Global warming is one factor blamed and local people say rainfall has been steadily reducing by about five to 10mm a year.
Other factors include irrigation and the damming of rivers feeding the lake for hydro-electric schemes, which have all combined to devastating effect.
"Desertification is moving southwards," said William Bata Ndahi, director of the Lake Chad Research Institute.
"The water is moving further and further away. We believe desertification has contributed most to the demise of Lake Chad."
He showed us a photo of a boat the research institute once used, moored next to a field office. But now the remains of the boat are grounded and the water is 60 miles away.
For the last 15 years the countries that border the lake have been talking about plans to replenish the lake.
A fifth country - the Central African Republic - joined them to form the Lake Chad Basin Commission.
Fishermen's livelihoods are under threat
Plans are under way to build a dam and 60 miles (97km) of canals to pump water uphill from the Congo River to the River Chari, one of the rivers that feed the lake, and then on to Lake Chad.
The project is highly ambitious and has taken years to raise the £3.5m needed for a feasibility study, which has not yet begun.
But engineer Wakil Bakar, managing director of the Lake Chad Basin Commission, has not lost his confidence.
"It is going to be a massive project, but the end result is what we're after," he said.
The countries are looking for international donors, and once the feasibility study is completed, fund raising will start in earnest. But will it actually happen?
"Why not?" Mr Bakar insists. "It will, definitely it will. This lake has to be saved. We know the benefit. We know how people have suffered. We know what we have lost.
"All the countries - Chad, Niger, Cameroon, and Nigeria - we know what we have lost. It's going to be a huge benefit to all of us."
But the omens for grand projects and Lake Chad are not good. The last time anyone tried a grand project was 30 years ago with the South Chad Irrigation Project.
We visited the huge power station at New Marte, a silent museum piece of 1970s technology, where now even the electric clocks have stopped.
The power station was to provide electricity to pump water from Lake Chad to irrigate 165,000 acres (668 sq km) of farm land.
But the scheme was doomed from the start - even before construction started, the lake had begun to recede.
Hundreds of miles of canals were built, but the canals were not lined and the water simply drained away into the desert. Only a third of the land was ever irrigated. The southern part of the lake dried up, and now the canals and the land are barren.
Currently only 800 acres - about 0.5% of the original project - is irrigated.
The village of Dugarri, home to more fishermen and farmers, is built on a large island and the houses were made of mud and straw.
Villagers crowded round to tell us that in the last few years alone the water level had dropped by about a metre, exposing more land for farming, but making the fishing all but impossible.
What future is there for the families who live around the lake?
"One advantage is that at least we've got somewhere to farm now," said one man, a fisherman turned farmer. "Before, the water covered the land and there was nowhere to farm."
Certainly where there is a decent water supply the land can be highly productive. Near the village we saw maize, rice, okra, sweet potatoes and cassava.
But a number of the farmers there complained that they have had no help with fertilisers or irrigation, and have to rely on residual water in the ground to make the land fertile.
"If we could, we would still be fishing," another man said. "But farming is all we can do now."
The village seemed full of children, but as we left I could not help wondering what the future held for them.
If the rains continue to fail, if temperatures continue to increase, and if the talk continues to stay just talk, then these children will have children of their own and there will be no lake left to save.